The invention relates to an endoscope having two functional units which are rotatable in relation to each other, and having an electric connecting element by which the two functional units are connected or are connectable electrically to each other.
In order to impart functions, such as a mechanical zoom or focus adjustment or a mechanical image horizon orientation, for example to video endoscopes, certain components of the endoscope have to be mounted rotatably. If said components also comprise or contact electronic connections or printed circuit boards, the respective electronic connections also have to be ensured between components or functional units which are rotatable in relation to one another. It is a challenge in this connection to provide an electric connecting element which permits an as resistance-free rotation as possible of functional units which are connected electrically to one another by the connection, and at the same time does not impair the electronic signal transmission between the functional units.
In order to transmit electric signals between endoscope components which are mounted rotatably with respect to one another, use is frequently made in the prior art of sliding contacts, in particular rotational sliding contacts, or flexible spring contacts. However, contacts of this type are subject to wear and are prone to malfunction. Furthermore, such contacts produce a high electrical impedance and capacitance at the contact points which also change during movement of the components. Such contacts are therefore suitable at most for low-frequency or frequency-independent electric signals. By contrast, contacts of this type are unsuitable for signals with frequencies in the MHz to GHz range, as are used in particular in order to permit a high data transmission rate. This is the case, for example, in video endoscopes or camera heads.